Does your vehicle have trouble shifting gears? If so, you likely have a problem with the transmission. Here are some ways to diagnose the problem, and how your mechanic will try to fix it.

Diagnosis

Start by trying to diagnose the problem to narrow it down to the transmission.

Identify Automatic Shifting Issues

You'll want to identify the issue that you are having and narrow it down to the transmission. Is the vehicle not going faster no matter how much gas you give it, or does the shifting between gears seems a bit delayed? This is known as delayed engagement, and it could be due to the transmission not making the shift automatically.

Identify Manual Shifting Issues

If you are trying to take the vehicle out of park and it simply will not do it, then this is an easy problem to blame on the transmission. A similar issue may be happening where the vehicle will not go into reverse even though you can move forward without an issue. Take your vehicle to a mechanic to have it repaired immediately if this is the case. 

Repairs

There are a couple things that a mechanic will do to try to fix the problem with a transmission that's not working right.

Change the Transmission Fluid

The first thing that will be done is to check the transmission fluid levels to make sure there is enough fluid in the system. The vehicle needs to be warm and idling while the vehicle is in park or neutral, which will show you the accurate fluid transmission levels. If the fluid is low, the mechanic will try putting in more fluid to bring it up to the proper levels. The mechanic will also check to see if the fluid is dark in color or smells as if it is burning. If the fluid itself is bad, the old fluid will need to be flushed and replaced with new fluid. 

Check the Vehicle Codes

Your mechanic will also plug a computer into the vehicle and see if there are any service codes that indicate if any parts of the transmission have gone bad. For example, the governor pressure solenoid may need to be replaced. If the part is not outputting the proper amount of pressure, it will set off a service code that identifies the problem so that the part can be replaced. Getting access to this part is not exactly easy, since you'll have to perform some disassembly of the transmission in order to get to it. 

For more information about auto transmissions, contact a local mechanic.